High confidence for deteriorating conditions to develop through Saturday with severe winter weather affecting the hills and mountains later Saturday and overnight into Sunday. High confidence for cold but improving conditions on Sunday. Medium confidence for timing of the next weather systems but high confidence for a transition back to milder weather during Monday.
Blizzards and whiteouts present challenging and serious conditions due to a combination of falling or blowing snow, strong winds and cold temperatures. They can be highly disorientating, often resulting in near-zero visibility with limited or no visual references and no distinction between ground and sky. Cliff edges and cornices may not be apparent, even close up. These conditions require very good navigational skills.
Heavy snow can lead to rapid changes in underfoot conditions and paths may become treacherous or hidden. It also brings very poor visibility and often makes navigation much more challenging. When deep snow accumulates progress is often time consuming and strenuous, significantly affecting the distance one can travel on foot. Deep drifts can develop if snow is combined with strong winds. A heightened avalanche risk is possible and avalanche reports should be consulted where available.
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.
Poor visibility presents challenging route finding conditions. Visibility could be significantly less than 50 metres in all directions with few or no visual references, especially on featureless moors or plateaux. Distances become hard to judge and cliff or cornice edges can be difficult to recognise. These conditions require good navigational skills. There is a risk of white-out conditions when mist or fog is combined with extensive snow cover.
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.
Severe weather conditions developing with blizzards to low levels and storm force winds over the summits.
|Chance of precipitation|
|1300m||SE 58 70||SE 58 72||SE 60 76||SE 69 88||SE 62 81||SE 55 72|
|900m||SE 42 54||SE 43 56||SE 47 63||SE 54 72||SE 49 67||SE 44 61|
|600m||SE 47 57||SE 42 51||SE 43 56||SE 53 70||SE 47 63||SE 41 57|
|300m||SE 31 47||SE 25 40||SE 22 37||SE 29 49||SE 28 48||SE 23 44|
|Glen||SE 14 32||N 5 12||NE 13 28||NE 9 25||E 11 27||E 13 29|
A bright start in the east but very cold with frost and ice lasting through the day. Some outbreaks of light rain or snow over western Argyll at first. Cloud thickens during the morning with rain sleet and snow spreading from the west across Argyll early afternoon then moving east to reach all other parts by dusk. The rain will fall onto frozen surfaces creating icy stretches then quickly turn to snow. The snow will soon become heavy with blizzard conditions setting in across the ranges and down to 200-300m. Blizzards continuing through the evening. Access roads will become snow covered through the evening.
60% clear of cloud at first, especially Rannoch Moor area and northern Trossachs but cloud soon forming across the summits above 700m with all summits shrouded by early afternoon. Extensive cloud lowering through the afternoon and evening to 200 or 300m.
Mainly moderate but quickly reducing poor with onset of snow then widely very poor, but zero visibility or white-out conditions expected to be sustained through the evening and night.
Very severe conditions developing on Saturday afternoon with a risk of being caught out. Blizzards and storm force winds all preceded by a spell of freezing rain to give a coating of ice will lead to very dangerous conditions.
Blizzards overnight will gradually die out leaving cloudy conditions with outbreaks of snow for first thing on Sunday morning. This will soon die out with bright spells developing but low cloud lingering the Argyll hills. Freezing conditions at all levels leading to slippery surfaces.
Southeasterly gales overnight with gusts 70mph easing to 20 mph gusts 30mph and turning into the southwest during the day.
All summits will be in cloud at first on Sunday morning but lifting to 700-900m during the day across eastern ranges. Cloud perhaps persisting at 600m over more western ranges.
Poor at first but improving to excellent once the snow clears away to leave excellent views across the snow covered ranges.